Finding a new H1 tire for the CPX method

The CPX method is a common method to assess the acoustic properties of road surfaces. The tires to be used with this method are specified in ISO/TS 11819-3. Unfortunately, tire H1 (AVON AV4), which is used to characterize the tire/road noise of heavy vehicles, is no more manufactured since the end of 2014. Hardness of tires increases with mileage and with age. So, the lifetime of the H1 tires still under use is limited, as they are approaching the upper limit of Shore hardness specified in ISO/TS 11819-3. This makes it necessary to find a suitable replacement for AVON AV4. Therefore, a consortium of all providers of CPX measurements in Germany made common efforts to find a new H1 tire. With project funding from the German Federal Highway Research Institute (BASt) a new H1 tire shall be found and tested. In addition, the procedure applied in this project shall be described as a roadmap for future transitions. The actions taken up to now and the findings of the project will be described.